Picker stick checking apparatus



Dec. 25, 1956 J. ROCKOFF 2,775,264

PICKER STICK CHECKING APPARATUS Filed June 19 1953 INVENTOR. JOSEPH ROCKOFF 49 ATT'Y.

United States Patent PICKER STICK CHECKING APPARATUS .loseph Rockotf, Dayton, Ohio, assignor to The Dayton Rubber Company, a corporation of Ohio Application June 19, 1953, Serial No. 362,901

11 Claims. (Cl. 139-161) The present invention relates to check straps for looms,

and more particularly to check straps for fiy shuttle straps.

Straps of this type have previously been made of leather either in the form of a strap having the ends bolted together and to the loom frameto form a loop, or in the. form of an endless band which surrounds the stick and is supported by friction fingers which restrict movement of the strap under the impact of thepicker stick. Since these straps are subjected to repeated impacts of the rapidly moving picker stick they must have sutficient strength,.flexibility, andresilience to provide the necessary restraining action upon the .stick without excessive wear and without excessive frictional drag. Furthermore, the strap must not be sensitive to changes in temperature or humidity as is generally the case with leather. In, the co-pending application of Henry M. Bacon, Serial No. 75,387, filed February 9, 1949, now U. S. Patent No. 2,698,032, a laminated rubber and fabric check strap construction is described which has made of cotton fabric either impregnated or coated with rubber compound. In accordance with applicants present invention it has been discovered that improved results may be obtained by the use of aparticular fabric construction for the inner and outer surface layers of the strap, or in other words, by modifying the nature of the, fabric layers which are in contact with thestick and the snubbing or friction fingers in the checking mechanism.

Applicant has discovered that improved performance and life of the check strap are obtained if the outer fabric layers are composed of a nylon fabric or a fabric made of a blend of nylon and cotton fibers. More particularly, applicant has discovered that nylon-cotton blends containing at least about 50 percent nylon and at least about 10 percent cotton, or in other words, containiug about 50 percent to 90 percent nylon fibers and The most fabric is woven with threads composed of nylon-cut t staple and cotton fibers in the proportion of about percent nylon and about 25 percent cotton. The fabric is preferably square woven and is applied to the check strap construction on the bias.

Applicant has further discovered that improved performance and life of the check strap may be obtained if the longitudinally extending strength cords which are sometimes included in transverse layers in check strap construction, are also composed of a nylon or nyloncotton blend similar to that above described.

Whether or not the longitudinal strength cords are employed in thestrap construction, applicant has discovered that optimum results may be obtained if the outer exposed surfaces of the strap are free from rubber or rubber-like material. This is particularly true where straps of this invention, being built and vulcanized in cylindrical form and tending to assume this, cylindrical shape during operation, are employed. As a result of the tendency of the strap to change from the pinched and elongated shape it is forced to assume between the snubbing fingers with which it will operate to the cylindrical shape in which it was built and vulcanized, a radial force is exerted by the outer surface of the strap against the snubbing finger which is contiguous therewith. This force likewise causes a forced contact between the inner surface of the strap and the snubbing fingers contiguous with it. Where a force normal to the contact surface between the strap and the snubbing fingers is thus provided, the checking does not depend so much upon the friction properties of the surface. It has accordingly been found feasible and desirable: to keep these outer surfaces free ofany frictioning material such as rubber, and this invention provides that the same be made up solely of a nylon containing fabric to achieve still more improved checking properties. In order that the fabric forming these outer surfaces of the strap may be properly adhered and vulcanized to the rest of the strap, it is, of course, permissible to friction the side of the fabric to be placed toward the interior of the strap.

To provide a protective coating for the edges of the check straps which will save them from the, deleterious effects of exposure to the atmosphere and abrasive contacts with other straps resulting in the fraying and wearing away of the fabric and cords exposed at these edges but at the same time, will not unduly increase their friction coefficient, the straps of the present invention are provided with a thin film of nylon about their edge surfaces. This coating may be provided in any convenient manner such as by spraying or painting the edges with a nylon solution or dispersion. A fused nylon coating may be conveniently provided where the nylon blend fabric and/or cords are employed as above described, by simply applying sufficient heat to the edges of the .strap to fuse the nylon in the fabric exposed to the heated edge. The heat necessary to fuse the nylon in the textile material exposed to the strap edges may be conveniently applied by placing the finally cut strap between heated platens which are maintained at a temperature sufiicient to cause fusion of the nylon but which are at the same time not so high as to cause any weakening thereof. Such temperature is preferably just below the melting point of the. nylon which will range from 409 F. to 496 F.

It is therefore an object of the present invention to provide an improved check strap construction having increased durability and improved performance.

It is a further object of the present invention to provide an improved check strap construction wherein .the strap will have a desired coefficient of friction when used with friction or snubbing fingers.

It is yet a further object of the present invention to provide an improved check strap the edges of which will have a desired coefiicient of friction when used in multiple,'"butwill at the same time be protected from the atmosphere and thedeterioratingeffect of the abrasion resulting from their rubbing together.

It is another object of the present invention to pro- -vide-a-method"for"the manufacture of the improved che'ck strap herein contained.

It is a still further object ofthis invention to provide an improved'checking mechanism incorporating the check'strap of this invention.

*The'checkstrap construction of'the present invention may be further described Withreference to the accompanyingdrawings,'inwhich:

Figure 1 isa view in perspective of an endless, cylindrical check strap" of the present invention.

' 1 Figure 2 is a cross-sectional view showing the construction *ofthe check strap taken along lines 22 of Figure, 1.

Figure 3 is an elevational view'of a portion of a loom showing the checking mechanism incorporating multiple check straps.

Figure 4 is a plan view in partial cross section of the checkingmechanism of Figure 3 taken along the line 4-4 thereof.

In Figure 1, the-check strap is shown in thecylindrical form it naturally assumes after having been built and vulcanizedwhileu'pon a cylindrical mandrel. In practice this strap will be forced to assume a pinched and elongated'shape'as it is gripped between the snubbing fingersof the checking mechanism in the manner of the strap shown in Figure 4. When the'strap is placed in operating position, it will be horizontallydisposed so that it'will'be engaged by the snubbing fingers along the surfaces12 and 12a, the edge surfaces 11 being exposed to the atmosphere or rubbing contact with other straps of 'themech'anism. As the strap moves back and forth between the snubbing fingers under the impact of the picker stick, it will tend to return to the cylindrical shape in which it was built and vulcanized; and this tendency has been found to provide a desired forced contact be- :tween the strap and the fingers thereby improving the effectiveness .of the checking mechanism.

The internal construction of thestrap is illustrated in the cross-sectional view shown in Figure 2. The outermost layers 1.2 and 12a are composed of the previously described nylon or nylon-cotton blend fabric which, as further set forth above,'are preferably free from any rubber-like material, on their outer surfaces so that slippage of these surfaces along the snubbing fingers will not be greatly inhibited. 'Interiorally of these outer fabric layers may be positioned a plurality of inner fabric layers preferably, but not necessarily, composed of the same material as outer layers 12 and 12a. In this preferred icr'nbodiment'of the present invention these interior fabric layers 13 and'13a are shown to be separated by layers of rubber or rubber-like'rnaterial such as 14 and 15. These rubber-like layersmay be applied separately in the construction of the strap or they may consist simply of skimcoating which has been applied'to the fabric prior to its being wound about the drum or mandrel in the buildingprocess.

At the central portion of the strap between thesefabric or alternating fabric and rubber layers is located a layer of longitudinally extending parallel cords 16 which are themselves preferably embedded between cushioning layers of rubber or rubber-like'material 17 and 18.

The. strap is formed by first preparing a cylindrical sleeve ofthede'sired dimensions made up of the various layers and then by cutting the sleeve into a plurality of bands or straps ofthe desired width and having a rectangular cross section. In the manufacture of the straps byithis method, adrum or mandrel is selected having a diameter conforming to the desired inner diameter of the strap. This mandrel is then wrapped with a layer of the-nylon'fabric12a and then with additional layers of fabric 13 and rubber-like material 14. Layer 12a is pref erably frictioned or skim coated on one side with a rubber compound and is' applied to the mandrel with the rubber coated side up so that the surface in contact with the mandrel does not have a rubber coating thereon. Successive layers of fabric may be impregnated or frictioned on both sides with or without skim coating. Fabric layer 12a is bias laid which means that the fabric is cut at an angle or bias to the direction of the threads or cordsand is applied to the drum with the threads at an acute angle to the longitudinal axis of the drum. The other fabric layer 13 may be either bias or laid straight.

Over the fabric layer or layers is superimposed a cushioning layer of rubber shown at 17. This layer is composed of unvulcanized compounded rubber and is of a fairly soft stock. Upon this cushioning layer is then wound a layer of cord 16. This cord layer is wound upon the mandrel in the form of a helix and has preferably been preliminarily treated or impregnated to improve its adhesive properties for rubber. This impregnation may be by treatment with rubber latex or rubber solutions or with a resorcinol-formaldehyde-latex composition as commonly used in the treatment of tire cord. The cord is wound spirally around the drum in a continuous manner, and the windings may be contiguous or spaced as desired.

Alternatively, the cord may be applied in'the form of a fabric in which parallel cords are held in spaced relationship by means of transverse pick threads. In such case, the cord fabric is coated or. embedded with rubber prior to application around the mandrel.

Another cushioning layer of rubber is then applied over the cord layer as shown at 18 in Figure 2. A plurality of fabric layers 13a and rubber layers 15 are then applied over cushioning layer 18 and an outer layer of fabric 12 applied last. The outer layer is a nylon containing fabric similar to layer 12a. Layers 13a may be cotton or nylon. Outer layer 12a is bias laid and layers 13 may be either straight or bias laid.

The assembled laminated layers on the mandrel are now rag wrapped to place the sleeve under pressure in order to obtain a unitary structure after vulcanization. This is accomplished by tightly winding strips of heavy fabric known as rag wrap material, around the assembly. The wrapped drum is then placed in an autoclave where it is vulcanized in the presence of steam in the conventional manner.

The various rubber materials composing the cushioning layers and the fabric coating or impregnating. material layers separating these fabrics have been compounded with vulcanizing agents, accelerating agents, pigments, fillers, and the like, as is well known in the art.

After vulcanization the assembly is taken from the autoclave and the wrapping removed. The cylindrical composite sleeve may then be removed from the mandrel and placed upon a cutting drum where it is cut into a plurality of bands or straps of the desired width, being severed cir cumferentially by knives spaced at the desireddistance. The resulting check straps are then removed from the mandrel. As shown in Figure 2, the side edges of the respective layers are exposed by the severing operation.

A preferred check strap construction is as follows:

Inner layer 1 ply square-woven 8 ounce nylon-cotton fabric; 2 ply Warp, and 2 ply'filler containing nyloncut staple percent, cotton 25 percent, frictioncd with rubber on the innersurface and with-the outer surface unrubberized. This fabric is bias cut andbias laid. This layer formsinner layer 11, the outer exposed surface of which is free from rubber. If desired, this layer may be frictioned or skimmed on one side with rubber to promote adhesion to the adjacent fabric layers.

3 plies rubberized square-Woven 8 ounce cotton fabric frictioned with neoprene on both sides and skim coated on one and bias laid.

-1 ply cushion layer of neoprene 1 ply all nylon cord 0.053 gauge 1 ply cushion layer of neoprene 3 plies rubberized square-woven 8 ounce cotton fabric frictioned on two sides, skim coated on one 1 outside ply of nylon fabric corresponding to inner layer 12 of Figure 2 and identical with inner layer 11 referred to above.

The above layers were assembled on a drum with frictioned and skimmed surfaces toward the center of the sleeve in the order given and wrapped, vulcanized, and cut in the manner described to form a plurality of check straps 9 inches long, /2 inch wide, and A inch thick. These individual check straps were then placed between the heated platens of a simple hand-operated press where their edge surfaces were heat sealed by the fusion of the nylon of the fabric and longitudinal cords exposed at these edges and in contact with the platens which were heated to a temperature of 480 F.

Check straps according to this invention, having their edge surfaces protected by a thin coating of fused nylon, are particularly desirable for use in multiple groups of 3 or 4 straps as shown in the checking mechanism illustrated in Figures 3 and 4. The individual straps 19, 19a and 19b are in a horizontally disposed position in superimposed relation so that each may act independently in checking the motion of the picker stick 20 carrying the loom picker 21 which will operate back and forth within the strap as the throw of the shuttle is halted and then thrown ina reverse direction.

Although the multiple check straps will operate independently they will be contiguously superimposed and will rub against each other along their edge surfaces. These straps will be primarily restrained, however, by the operation of the depending snubbing fingers such as 22 and 22a which are mounted upon the loom table 25 in a fixed position. These particular fingers are so arranged that they will contact the inner periphery of the check straps and in order that they may exert the desired force against this inner periphery of the straps, additional snubbing fingers 23 and 23a are provided to engage the strap about their exterior periphery at a point midway between the interior fingers. These exteriorly located fingers such as 23 and 23a are preferably mounted upon a horizontally disposed lug 24 which is provided with a slot to allow the lateral adjustment of the snubbing fingers 23 and 23a so as to control the force which they will exert upon the exterior surface of the strap.

It is to be understood that these check straps may also be used as individual wide bands between snubbers in the manner shown, for example, by Patent No. 1,341,941 or No. 2,393,148.

By the use of the inner and outer surface layers of the nylon fabric referred to, applicant has been enabled to produce check straps giving substantially improved performance over check straps made using cotton and the like, as was the prior practice. The outer surface of the nylon-cotton fabric which is in contact with the snubbers and with the stick is preferably free from rubber. The resulting construction has been found to give the proper coefficient of friction and degree of drag in a checking mechanism of the type in which snubbers are used as described in the art referred to above. This results in proper positioning of the looms. Furthermore, the coefficient of friction must not change with age or wear.

and this has been found to be the case in the construction of the present invention.

In preparing the cushioning layer described herein, or in rubberizing the. fabric or cords, either natural or synthetic rubber as well known to the art may be used. The term rubber as used herein is intended and does include natural rubber as well as the synthetic rubberlike and vulcanizable elastic materials known as synthetic rubber, including the rubber-like conjugated butadiene hydrocarbon polymers and copolymers with styrene, ac-

rylonitrile or other monomers copolymerizable therewith containing an active CH2=C group, the halogenated diolefin polymers of the chloroprene type known as neoprene, the polysulfiderubbers of the thiokol type, and the isobutylene-diolefin copolymers of the butyl rubber type.

While the foregoing structure has been described in connection with a continuous annular member, it may also be utilized in the fabrication of check straps of other types, for example, a non-endless type where the strap is fastened at both ends to the loom in the manner set forth, for example by Patent No. 2,291,587, or the like.

I claim:

1. A loom check strap comprising a laminated rubber and fabric annular body the outermost layers of which are of nylon containing fabric, a centrally positioned layer of longitudinally arranged nylon-containing reinforcing cords and a thin coating of fused nylon about the edge portion of said body.

2. A check strap construction according to claim 1 wherein the nylon containing fabric contains at least 50 percent nylon and at least 10 percent cotton.

3. A check strap construction according to claim 1 wherein the nylon containing fabric contains approximately percent nylon in the form of cut staple and 25 percent cotton.

4. A check strap construction according to claim 3 wherein the nylon fabric in the outer surface layers is bias laid.

5. A loom check strap comprising a laminated rubber and fabric body, a centrally positioned layer of longitudinally arranged nylon-containing reinforcing cords and a thin coating of fused nylon about the edge portions of said body.

6. A loom check strap comprising superimposed laminae of rubber and of fabric at least some of which are nylon-containing and a thin coating of fused nylon about the edge portions of said body.

7. A loom check strap comprising a laminated rubber and fabric body the outermost layers of which are of fabric and a thin coating of fused nylon about the edge portions of said body.

8. A method for the manufacture of loom check straps comprising forming a cylindrical sleeve of rubber and nylon-containing fabric layers, cutting individual straps from said sleeve and subjecting the cut edges to elevated temperatures to fuse the nylon at the exposed edges of said fabric layers, and spreading said fused nylon over the cut edges of the straps.

9. A method for the manufacture of loom check straps comprising forming a cylindrical sleeve of rubber and nylon-containing fabric layers, cutting individual straps from said sleeve and subjecting the cut edges to heated platens the temperature of which is above the melting point of the nylon, whereby fusion of the nylon at the exposed edges occurs, and spreading said fused nylon over the cut surfaces of said straps.

10. A method for the manufacture of loom check straps comprising forming a body of rubber and of nylon-containing laminae, subjecting the edges of said body to elevated temperatures to fuse the nylon at the edges of said laminae, and spreading said fused nylon over the edges of said body.

11. A method for the manufacture of loom check straps comprising forming a body of laminated rubber and fabric layers and spreading a coating of fused nylon over the edges of said body.

References Cited in the file of this patent UNITED STATES PATENTS 2,349,290 Loughborough May 23, 1944 2,426,353 Johnson Aug. 26, 1947 2,435,749 Lesesne Feb. 10, 1948 2,505,354 Gartrell et al. Apr. 25, 1950 2,519,590 Mitchell Aug. 22, 1950 2,628,412 Vera Feb. 17, 1953 

